After i changed the head of my engine, the fuel consumption is through the roof.

[Tor-Lein]

Ref: Piston Analysis

After i changed the head of my engine, the fuel consumption is through the roof..
I can only drive 150 miles on a full tank of gas, 100 miles less than before.

I have no idea why it consumes so much, but im guessing some kind of sensor?

Anyone had the same problem beforee?
What could cause this bad mpg?

Thanks..

 

[rstare]

Any other symptoms besides bad mileage?
I would say first thing to check would be 02 sensor.

 

[silvreclips]

do you have a CEL on? I would test the front o2 sensor, make sure its even plugged in. Maybe check the coolant sensor also.

 

[Locke]

After checking what these guy's mentioned, make sure that you are developing adequate vacuum.

 

[Dsmj89]

Check your o2 sesnor, any vacuum leaks, and if you haven't changed your fuel filter do so as well.

 

[wrknmike924]

What kind of head did you put? Was it remand or anything? do you have aftermarket cams?

 

[jrohner]

Go by MPG, not miles per gas gauge. On the 2g non-turbo I had before, I could easily go 400+ on a tank. I could drive 50 miles on E with the light on and it still wasn't near empty. The only car I've ever drove to 36MPG


o2 sensor, thermostat, head gasket not sealing, valves not sealing, cam timing off, exhaust leak (throws off the o2 sensor), it could be many things.

Have you done a compression test? Does the car reach normal operating temperature? Does your o2 sensor cycle correctly?

 

[ricerrocket]

mine gets about 180-200 per tank, is it idleing a lot higher thats what mine did.

 

[Defiant]

Cam timing's off.

 

[wrknmike924]

Cam timing's off.

I would have to agree. Sounds like your valves arent opening when they are supposed to. or closing.

 

[EclipticalGS]

How does the car run?? does it sound like its off on timing??

 

[edgar420a]

the computer might not be going into closed loop. when this happens it eats up your gas. use a scaner to see if the monitors are all set to ready. Good luck

 

[Tor-Lein]

Well, the timing is spot on, the idle is good (about 800rpm), the engine sounds great and vacuum is fine.
Head is all stock, from CI. Im running 98 octane, which is what we have in pumps here in Norway.
Ill check the O2 sensors, change fuel filter and sparkplugs.

Thanks for helping me!

 

[rstare]

Well, the timing is spot on, the idle is good (about 800rpm), the engine sounds great and vacuum is fine.
Head is all stock, from CI. Im running 98 octane, which is what we have in pumps here in Norway.
Ill check the O2 sensors, change fuel filter and sparkplugs.

Thanks for helping me!

Just for clarification, what are your vacuum readings?

 

[Tor-Lein]

Ill check my vacuums again this weekend, but they were fine according to Haynes manual.
Can't remember the exact numbers, but ill throw them out here when i have checked again.

Im going to hook up my laptop and se how much it's consuming, i can't afford this milage with $6.20 per gallon here in Norway..

OT: We dont use gallons, but litres. 1gallon ~ 4litres. One dollar ~ 7 norwegian kroner (NOK).
1litre gasoline 11NOK * 4 = 44 NOK per gallon. 44 / 7 = $6.20 per gallon.

We have kind of high gas prices you see...